<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
    <!-- <div data-Id="1">我要增加一个自定义属性</div> -->
  <!-- 账号：<input type="text" placeholder="请输入用户名" value="admin">
  <br>
  密码：<input type="text" placeholder="请输入密码" value="123456">
  <br> -->
  <script>
//  const username = document.querySelector('[value="admin"]')
//     const password = document.querySelector('[value="123456"]')
//     const user = {
//       username: username.value,
//       password: password.value
//     }
//     console.log(user)
    // const div = document.querySelector('div')
    // console.log(div.dataset.id)  // 要求输出 1
  </script>
</body>
</html>